2,005 research outputs found

    Data-informed Open Education Advocacy: A New Approach to Saving Students Money and Backaches

    Get PDF
    The North Carolina State University Libraries has long recognized the financial burden textbook costs place on students. By crosswalking information on use of our textbook collection with textbook cost and course enrollment data, we have begun to map the environment for textbook use at the university and identified opportunities for faculty outreach in promoting alternatives to traditional textbooks, including our Alt-Textbook program. This article describes our programs, our investigation of textbook use patterns, and how we are using these data to inform our practice

    Prophetic Call and Message of Bartolome De Las Casas (1484-1566)

    Get PDF
    Histor

    Studies on the mechanism of catalysis of iron-sulfur cluster transfer from IscU[2Fe2S] by HscA/HscB chaperones

    Get PDF
    The HscA/HscB chaperone/cochaperone system accelerates transfer of iron-sulfur clusters from the FeS-scaffold protein IscU (IscU(2)[2Fe2S], holo-IscU) to acceptor proteins in an ATP-dependent manner. We have employed visible region circular dichroism (CD) measurements to monitor chaperone-catalyzed cluster transfer from holo-IscU to apoferredoxin and to investigate chaperone-induced changes in properties of the IscU(2)[2Fe2S] cluster. HscA-mediated acceleration of [2Fe2S] cluster transfer exhibited an absolute requirement for both HscB and ATP. A mutant form of HscA lacking ATPase activity, HscA(T212V), was unable to accelerate cluster transfer, suggesting that ATP hydrolysis and conformational changes accompanying the ATP (T-state) to ADP (R-state) transition in the HscA chaperone are required for catalysis. Addition of HscA and HscB to IscU(2)[2Fe2S] did not affect the properties of the [2Fe2S] cluster, but subsequent addition of ATP was found to cause a transient change of the visible region CD spectrum, indicating distortion of the IscU-bound cluster. The dependence of the rate of decay of the observed CD change on ATP concentration and the lack of an effect of the HscA(T212V) mutant were consistent with conformational changes in the cluster coupled to ATP hydrolysis by HscA. Experiments carried out under conditions with limiting concentrations of HscA, HscB, and ATP further showed that formation of a 1:1:1 HscA-HscB-IscU(2)[2Fe2S] complex and a single ATP hydrolysis step are sufficient to elicit the full effect of the chaperones on the [2Fe2S] cluster. These results suggest that acceleration of iron-sulfur cluster transfer involves a structural change in the IscU(2)[2Fe2S] complex during the T --> R transition of HscA accompanying ATP hydrolysis

    Enzyme evolution: innovation is easy, optimization is complicated

    Get PDF
    Enzymes have been evolving to catalyze new chemical reactions for billions of years, and will continue to do so for billions more. Here, we review examples in which evolutionary biochemists have used big data and high-throughput experimental tools to shed new light on the enormous functional diversity of extant enzymes, and the evolutionary processes that gave rise to it. We discuss the role that gene loss has played in enzyme evolution, as well as the more familiar processes of gene duplication and divergence. We also review insightful studies that relate not only catalytic activity, but also a host of other biophysical and cellular parameters, to organismal fitness. Finally, we provide an updated perspective on protein engineering, based on our new-found appreciation that most enzymes are sloppy and mediocre

    The Murdoch-Godfrey Letters of 1869: A Nova Scotia - Maine Historical Correspondence

    Get PDF
    An introduction, source notes, and transcription of three letters from Beamis Murdoch in Halifax, Nova Scotia, to John Edward Godfrey in Bangor, Maine, February 8 to 27, 1869

    Study protocol for a double blind, randomised, placebo-controlled trial of continuous subpectoral local anaesthetic infusion for pain and shoulder function following mastectomy: SUB-pectoral Local anaesthetic Infusion following MastEctomy (SUBLIME) study.

    Get PDF
    INTRODUCTION: Over 16 000 mastectomies are performed in England and Wales annually. Acute postoperative pain and nausea are common. The most frequently occurring long-term complications are chronic pain (up to 50%) and reduced shoulder function (reported at 35%). Regional techniques that improve acute postoperative pain relief may reduce the incidence of these complications. This study assesses the effectiveness of a 24-hour continuous local anaesthetic in the subpectoral plane in improving postoperative pain and quality of life in patients undergoing mastectomy. METHODS AND ANALYSIS: This is a randomised, double blind, placebo-controlled, two-centre, parallel group trial in women undergoing mastectomy with or without axillary involvement. One hundred and sixty participants will be randomised in a 1:1 ratio to receive either 0.25% levobupivacaine or 0.9% saline by subpectoral infusion postoperatively for 24 h. All participants will be provided with an intravenous morphine patient-controlled analgesia (PCA) system. Participants will be followed-up for 24 h in hospital and at approximately 14 days and 6 months postoperatively. Joint primary outcome measures are total morphine consumption and total pain score (captured via patient-recorded visual analogue scale (VAS) 4 hourly) during the first 24 h postoperatively. Primary statistical analysis of total pain is based on the area under the curve of pain versus time graph. Secondary outcomes include PCA attempts in first 24 h; VAS pain scores and shoulder function by goniometry at 24 h, 14 days (approximately) and 6 months; Verbal Rating Scale pain scores in first 24 h; Brief Pain Inventory and Oxford Shoulder Score at 6 months; duration of hospital stay; incidence of postoperative nausea and vomiting; cost-effectiveness. ETHICS AND DISSEMINATION: The study is approved by the South West England Research Ethics Committee (12/SW/0149). RESULTS: will be published in a peer-reviewed journal and presented at local, national and international scientific meetings. TRIAL REGISTRATION: ISRCTN46621916. EudraCT 2011-005775-16

    Investigative Tools and Techniques for Indoor Air Quality Studies

    Get PDF
    Indoor air quality problems are diverse and often complex. Adverse indoor air quality problems can exist which create symptomatic conditions for building occupants. Often, the exact cause, or causes, of the substandard indoor air quality are unknown. Therefore, an investigative approach must usually be taken to identify the source(s) of the air quality problem, and if present, air contaminant concentrations. As the general public becomes more aware of the problems associated with poor indoor air quality conditions, an associated increase in air quality evaluation requests can be expected. This paper discusses some of the various investigative tools and techniques that can be utilized to identify air quality contaminants when performing an indoor air quality evaluation. These investigative tools and techniques can be used to develop a site specific list of possible contaminants and their sources, and can then be used to determine which contaminants are, in fact, present in adverse concentrations. Some of the investigative tools and techniques to be discussed in this paper include the following: visual inspections and site observations, information searches, review of building construction, review of ventilation systems, interviews, low and high volume sampling pumps, flow and oxygen meters, portable photoionization and flame ionization detectors (PID & FID), various types of vapor detector tubes, and gas chromatograph/mass spectrophotometer (GC/MS) analysis. This paper will be an introductory overview of the above listed investigative tools and techniques. The paper's attempt is to acquaint the reader with these investigative tools and techniques, and how they can assist the reader in an air quality evaluation

    Metatranscriptomic analysis reveals active bacterial communities in diabetic foot infections

    Get PDF
    Despite the extended view of the composition of diabetic foot infections (DFIs), little is known about which transcriptionally active bacterial communities are pertinent to infection, and if any differences are associated with increased infection severity. We applied a RNA sequencing approach to analyze the composition, function, and pathogenicity of the active bacterial communities in DFIs. Taxonomic profiling of bacterial transcripts revealed the presence of 14 bacterial phyla in DFIs. The abundance of the Spiroplasma, Vibrio, and Mycoplasma were significantly different in different infection severities (P < 0.05). Mild and severe stages of infections were dominated by Staphylococcus aureus and Porphyromonas asaccharolytica, respectively. A total of 132 metabolic pathways were identified of which ribosome and thiamin being among the most highly transcribed pathways. Moreover, a total of 131 antibiotic resistance genes, primarily involved in the multidrug efflux pumps/exporters, were identified. Furthermore, iron acquisition systems (synthesize and regulation of siderophores) and pathways involved in the synthesis and regulation of cell-surface components associated with adhesion, colonization, and movement of bacterial cells were the most common virulence factors. These virulence factors may help bacteria compete for scares resources and survive the host wound proteases. Characterization of transcriptionally active bacterial communities can help to provide an understanding of the role of key pathogens in the development of DFIs. Such information can be clinically useful allowing replacement of DFIs empirical therapy with targeted treatment

    The Rescue of Fannie Mae and Freddie Mac

    Get PDF
    Staff Report including the following:- Describes and evaluates the measures taken by the U.S. government to rescue Fannie Mae and Freddie Mac in September 2008. - Outlines the business model of these two firms and their role in the U.S. housing finance system. - The sources of financial distress that the firms experienced and the events that ultimately led the government to take action. - Describes the various resolution options available to policymakers. - Evaluates the success of the choice of conservatorship and other actions taken
    corecore